Quality of life (“QOL”) is commonly defined as the level of enjoyment, comfort and health in a person's life. QOL is studied as part of psychology, sociology, social psychology and culture. QOL, as a cultural creation, is also extremely commercialized.
In a subjective sense, QOL is determined by factors that are perceived in such a way as to provide a person with an overall feeling of happiness and general sense of well being and satisfaction. Determinations of quality of life are highly subjective and individualized, as different individuals will value particular aspects of their life more than others will value those same aspects in their own lives.
Thus an objective QOL measure is difficult to define. Various indices exist which attempt to measure the quality of life of an individual or aggregate quality of life of a population. These indices are based on a number of factors, some of which are highly subjective, such as surveys of people's perception of their family life, while others are more objective, such as statistical data of average household income in a given region.